Heretofore, in an automated assembly line for automobiles, an assembly process has been carried out in which clamping is performed by a clamp apparatus for overlaying and positioning a plurality of preformed body panels, and then the body panels are welded together.
The present applicant has proposed an electric clamp apparatus as disclosed in Japanese Laid-Open Patent Publication No. 2005-169604. In the electric clamp apparatus, a clamp arm is provided for rotation on a body equipped with an electric motor, and a rotary drive force of the electric motor is transmitted through a speed reducing drive system, whereby the clamp arm is rotated for clamping a workpiece.